HARTFORD, Conn. (AP) — U.S. Sen. Richard Blumenthal is calling for stronger government oversight of so-called “compounding pharmacies” amid a meningitis outbreak in several states that has killed seven people.

The Connecticut Democrat said Sunday that he will be writing to U.S. Food and Drug Administration Commissioner Margaret Hamburg to ask for stricter scrutiny of such pharmacies. He said the facilities appear to operate in a “regulatory black hole” and are only marginally overseen by the FDA.